Let's say an investor has a capital of $1000000$ euros and is considering whether it is beneficial for him to invest for $3$ months in euros $($domestic currency$)$ or sterling $($foreign currency$).$ The current exchange rate is $1$ sterling $=1\mathrm{.}42$ euros. The $3-$month interest rate of the euro on an annual basis is $3\%.$ The $3$ month interest rate for sterling on an annual basis is $4\%.$ The $3-$month forward rate is $1$ sterling $=1\mathrm{.}39$ euros. What should the investor decide?